若m,n为正整数,且x^2m=3,x^n=5,求2x^2m-2n的值

问题描述:

若m,n为正整数,且x^2m=3,x^n=5,求2x^2m-2n的值

2x^2m-2n
=2x^2m/x^2n
=2×3/5²
=6/25